noun🔗Share天然碱，泡碱。 Native sodium carbonate; natron."The ancient Egyptians used niter, gathered from dry lake beds, to help preserve mummies. "古埃及人使用从干燥湖床采集的**天然碱（泡碱）**来帮助保存木乃伊。chemistrymineralsubstancegeologyChat with AIVocabulary GamePractice Reading
noun🔗Share硝石，火硝 A mineral form of potassium nitrate (saltpetre) used in making gunpowder."The old chemistry book described how niter, found in certain caves, was a key ingredient in making gunpowder for cannons. "这本旧化学书描述了如何在某些洞穴中发现的硝石（火硝），是制造大炮火药的关键成分。mineralsubstancechemistrygeologyweaponmaterialChat with AIVocabulary GamePractice Reading
